Production of aqueous solutions of mixtures of formyltertrahydrofuran and hydrates thereof

Abstract

Disclosed is a process for the recovery of formyltetrahydrofurans (FTHF's) produced by the rhodium-catalyzed hydroformylation of 2,5-dihydrofuran (2,5-DHF) wherein the FTHF's are recovered as an equilibrium mixture of 2- & 3-FTHF and their hydrates, 2- and 3- di(hydroxy)methyl!tetrahydrofuran from a hydroformylation product solution comprising a rhodium catalyst, 2- and 3-FTHF and an organic hydroformylation solvent obtained as a liquid product take-off from a hydroformylation process wherein 3-FTHF is produced by the hydro-formylation of 2,5-DHF 3-FTHF is a valuable organic intermediate useful, for example, in the preparation of 3-methyltetrahydrofuran and 3-amino-methyltetrahydorfuran.

I claim: 
     
       1. Process for producing an aqueous solution, essentially devoid of alkanol, containing a mixture of compounds having the formulas: ##STR5## which comprises (1) intimately contacting a hydroformylation product solution comprising (i) 20 to 80 weight percent of an aldehyde of formula (I), (ii) hydroformylation catalyst components comprising rhodium and an organophosphorus compound, and (iii) 80 to 20 weight percent of a hydroformylation solvent with water essentially devoid of alkanol; (2) allowing the mixture of step (1) to separate into 2 phases; and (3) separating the 2-phases to obtain (a) a hydroformylation solvent phase containing catalyst components and (b) a water phase containing the compounds of formulas (I) and (II); wherein the volume ratio of water to hydroformylation product solution employed in step (1) is about 0.1:1 to 4:1; the hydroformylation product solution employed in step (1) contains less than about 15 weight percent of 2,5-dihydrofuran (2,5-DHF), 2,3-dihydrofuran (2,3-DHF), tetrahydrofuran (THF), or a mixture of any 2 or more thereof; and the mole ratio of compound (I) to compound (II) is about 0.05:1 to 20:1. 
     
     
       2. Process according to claim 1 wherein the hydroformylation solvent has a density in the range of about 0.6 to 0.9 and is selected from esters having about 6 to 20 carbon atoms, alkanes having about 5 to 20 carbon atoms, ketones having 6 to 20 carbon atoms, dialkyl ethers and cyclic ethers having 5 to 20 carbon atoms, alkyl-substituted benzenes having about 7 to 15 carbon atoms, tetrahydronaphthalene, and decahydronaphthalene. 
     
     
       3. Process according to claim 2 wherein the aldehyde of formula (I) constitutes about 50 to 70 weight percent of the total weight of the hydroformylation product solution.